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x402lint

Registre officiel Autres

Free x402 endpoint linter: checks the unpaid 402 challenge, payTo/asset/amount, CORS, discovery.

Code source Site web Documentation

Installation

Ajoutez ceci à la configuration MCP de votre client (Claude Desktop : claude_desktop_config.json ; Cursor : .cursor/mcp.json ; VS Code et les autres utilisent la même forme « mcpServers »).

Remote (streamable-http)
Claude Code 
claude mcp add --transport http x402lint 'https://x402lint.something-agent.workers.dev/mcp'
Configuration JSON (Claude Desktop, Cursor, VS Code) 
{
    "mcpServers": {
        "x402lint": {
            "type": "http",
            "url": "https://x402lint.something-agent.workers.dev/mcp"
        }
    }
}

Documentation

Tirée du README du projet sur GitHub, actualisée chaque semaine. Les liens ouvrent GitHub.

Sommaire
  1. x402lint
  2. What it checks (rule ids at /v1/rules)
  3. API
  4. Limits (honest)
  5. Develop

x402lint

Free, read-only linter for the unpaid path of an x402 endpoint. Point it at a paid URL and it tells you what a client or a directory would trip over, before you announce it. It never pays and never signs, so it cannot test settlement.

curl -H 'user-agent: me/1.0' 'https://x402lint.something-agent.workers.dev/v1/lint?url=https://mart402.com/v1/extract'

What it checks (rule ids at /v1/rules)

  • Challenge: x402Version, accepts[] required fields (v2 amount, v1 maxAmountRequired), CAIP-2 network, testnets, payTo format (EIP-55 checksum, zero/burn, equals the asset contract, Solana base58 length), amount is an integer in base units (and price for known USDC), asset/network pair, EIP-712 extra.name/extra.version for EIP-3009 USDC (and known-USDC values), maxTimeoutSeconds, v2 resource, bazaar extension, header vs body delivery.
  • Transport: GET vs POST both answer 402 and agree, redirects, plain http, cacheable 402, content-type, slow challenge, CORS (expose PAYMENT-REQUIRED, preflight allows PAYMENT-SIGNATURE).
  • Discovery: /.well-known/x402 payTo agrees with the live challenge, /llms.txt, /openapi.json.

API

  • GET /v1/lint?url=<paid URL>[&method=auto|GET|POST] fetch and lint.
  • POST /v1/lint/payment-required {"payment_required": <object | JSON string | base64 PAYMENT-REQUIRED header>, "url"?} lint a challenge you hold, no network.
  • POST /mcp Streamable HTTP MCP (stateless): lint_x402_endpoint, lint_payment_required.
  • Output: {verdict: ok|warn|fail, counts, summary, probes, findings[{id, severity, message, fix?, where?}], not_tested[]}.

Limits (honest)

  • Unpaid only. A clean lint is not proof the route settles or delivers. It does not call a facilitator.
  • Only the host in the URL (plus its /.well-known/x402, /llms.txt, /openapi.json) is fetched. About 6 subrequests per call (cap 40). 256 KB read per response. Best-effort per-IP limit.
  • Cloudflare: a Worker on workers.dev cannot fetch another *.workers.dev Worker of the same account, so those hosts appear unreachable. Send a named User-Agent (default Python-urllib UAs hit Cloudflare error 1010 on workers.dev).
  • Rules encode the current v2 transport and well-known USDC deployments (Base, Base Sepolia, Ethereum, Polygon, Arbitrum, Optimism, Solana). Opinionated items are info, not error. Disagree with a rule? Open an issue.

Develop

npm install && npm test && npm run typecheck
npx wrangler deploy      # Cloudflare Workers Free; no secrets, no bindings

MIT. By something, an independent agent operation.

Questions fréquentes

Qu'est-ce que x402lint ?

Free x402 endpoint linter: checks the unpaid 402 challenge, payTo/asset/amount, CORS, discovery.

Comment installer x402lint ?

Il fonctionne comme serveur distant. Dans Claude Code : claude mcp add --transport http x402lint 'https://x402lint.something-agent.workers.dev/mcp'. Pour les autres clients, collez la configuration JSON de cette page dans leurs réglages MCP.

Faut-il une clé API pour x402lint ?

Son entrée au registre n'indique aucune clé ni secret obligatoire. Certaines fonctions peuvent tout de même demander un compte auprès du service auquel il se connecte.

x402lint est-il open source ?

Oui. Son code est sur GitHub sous licence MIT.

Qui maintient x402lint ?

Il est publié par something-agent. AI.tn le référence sans le maintenir ni le recommander.

Issu du registre MCP officiel. Être listé n'est pas une recommandation : vérifiez le code et les permissions d'un serveur avant de lui donner accès à vos données.